Rotary drilling-tool.



C. P. MAYNER.` .ROTARY DRILLING TOOL.

APPLICATION msu MAR. 4, ma.

Patented Jan. 28,1919.

CHARLES P. MAYNEI'B., OF MONTEBELLO, CALIFORNIA.

ROTARY DBILLINGMTOOL.

Specication of Letters Patent.

Patented J an. 28, 1919.

Application led March 4, 1918. Serial No. 220,388.

To all whoml z't may concern:

Be it known that I, CHARLES P. MAYNER, a citizen of the United States,residing at Montebello, in the county of Los Angeles and State ofCalifornia, have invented a new and useful Rotary Drilling-Tool, ofwhich the following is a specication.

My invention relates to rotary drills, being more particularly a form offish tail bit,` and the mountin of the same. In common forms of fishtail bits the bits are provided at their upper end with a threaded shankwhich is threaded into a collar mounted on the lower end of the drillpipe.

This shank is of considerable size, and when the bit is worn down toV apoint where the same is useless for drilling purposes the discarding ofsuch a bit entails a loss of considerable metal.

One of the main objects of my invention is to produce a bit which may bequickly attached and detached, the bit being of extremely simple formand construction, having therein a minimum amount of metal.

Referring to the drawings, which are for illustrative purposes only,

Figure 1 is a vertical sectional view of a drilling device embodying aform of my invention.

Fig. 2 is a view similar to Fig. 1 showing the bit in the position forremoving the same.

Fig. 3 is a vertical 3-3, Fi 1.

Fig. 4 is a sectional plan view on line 4-4 of Fig. 1.

Fig. 5 is a sectional Fig. 1, and

Fig. 6 is a sectional plan view on line 6-6 of Fig. 1.

Fig. 7 is a fragmentary perspective view of the bit and its supportingrod.

10 designates a bit, the blade of which is of the common fish tailvariety, having a flat shank 11 which fits into a recess 12 formed inthe lower end of a head 13. 14 designates a rod which slidably extendsthrough a. central bore in the head 13, the lower end of the rod 14extending into a hole formed in the upper end of the bit. 16 designatesa pin which extendsv through a hole 17 formed in the shank 11, the pin16 extending through a hole 18 formed in the rod 14 thereby fixing thebit to the rod 14. y

sectional view on line plan view on line 5 5,

' Ihe head 13 is recessedat its upper end, as indicated at 20, and isexteriorly threaded, as indicated at 21, for attachment to the lower endof a barrel 22 which may be sea shoulder 26 formed in the head 13, the

tension of the spring 25 being sufficient to hold the shank 11 firmly inthe recess 12 in the lower end of the head. The upper end of the rod 14and the spring 25 are prcferably protected from dirt and otherobjectionable matter by means of a section of pipe 30 threaded into theupper end of the head 13, the upper end of the pipe 30 being closed by acap 31. The lower end of the head 13 is slotted as indicated at whichreceives a shouldered portion 34 of the bit 10, such construction givingadditional strength in the connection between the bit and head.

When it is desired to replace a bit, the bit is pulled downwardly fromthe position shown in Fig. 1 to that shown in Fig. 2 by placing a hookor other suitable fastening means through an eye 35 formed in the bit.When the bit is so extended a bar or pin 36 is inserted through anopening 37 in one side of the head 13, the bar 36 extending into anelongated slot or opening 38 in the rod 14, as shown in Fig. 2, in whichposition the tension of the spring 25 is taken by the bar 36. The pin 16may now be easily removed as the same is in the slotted portion 33 ofthe head 13, a suitable tool, as indicated at 40, being placed in theposition shown and the pin 16 driven out after which the bit 10 may beremoved from the rod 14 and a new one placed upon the rod, the pin 16being driven into place, the tension against the bar 36 relieved bypulling the bit slightly downwardly, the bar 36 removed and the shank ofthe bit allowed to enter the recess in the lower end of the head untilthe shouldered portion 34 of the bit is seated in the slotted portion 33of the head 13.

A bit so made and mounted may be very quickly replaced and the amount ofmetal in the shank 11 being materially reduced over that in the commonforms of bit. A bit so formed is economical and `superior to the commonforms of bit now same.

What ll claim is 1. A drilling tool comprising a head hav'- ing a recessin its lower end, a bit, a shank on the bit slidably extending into therecess, means forsecuring the bit to-the head,

said means comprising a rod slidably ex-` tending into the head, elasticmeans for holding the rod in upward position and a removable pinextending through the shank i and rod, and means for holding said rod inextended position to permit said bit to be removed from. the rod. Y,

2. A ldrilling tool comprising a head having a recess in its lower end,a bit, a shank on the bit slidably extending into the recess, means forsecuring the bit Ato the head, said means-comprising a rod slidablyextending through the head, a removable pinextending through the shankand rod, a coiled spring on said rod, and means on the upper end of saidrod for confining said spring to exert an upward tension on the rod, andmeans for holding said rod in extended position to permit said bit to beremoved from the rod.

3. A drilling tool comprising a head having a recess in its lower end, abit, a shank on the bit slidably extending into the recess, and meansfor securing the bit to the head, said means comprising a rod slidablyextending through the head, a removable pm extending through the shankand rod, a coiled spring` on said rod, and means on the upper end ofsaid, rod f or confining said spring to exert an upwardtension on therod, said rod having an elongated opening therein and said head having atool receiving opening therein to register with the elongated opening inthe rod when the bit is in extended position. Y

4. A drilling tool comprising a head having a recess 1n its lower end, aremovable bit, a shank on the bit slidably extending into the recess,means for securing the bitl to the head, said means comprising arodslidably extending centrally into the head,

elasticmeans for holding the rod in upward position and a removable' pinextendlng through the shank and rod, a shouldered portion on said bit,said head having a slotted portion adapted to receive the shouldered.portion of the bit, and means whereby said rod may be retained inextended position in the head to permit said bit to be removed from therod.

In testimony whereof, I have hereunto s et l my hand at Los Angeles,California, this 20th day of February, 1918.

CHARLES MAYNER.

